A. A. Saeed, et al.: Neutron Shielding Prop erties of a Borat ed High-Density ... 120 Nuclea r Technol ogy & Ra dia tion Pro tection: Year 2017, Vol. 32, No. 2, pp. 120-126 NEUTRON SHIELDING PROP ER TIES OF A BOR ATED HIGH-DENSITY GLASS by Aly Abdallah SAEED 1, Raed Mohamed El SHAZLY 2, Mohamed Mahmoud El-OKR 2, Ali Moheeb Abou El-AZM 2, Yahia Hamdy ELBASHAR 3*, Mohamed Nasef Hassan COMSAN 4, Wagdy Ahmed KANSOUH 4, and Ahmed Reda EL-SERSY 5 1 Nu clear Power Sta tions De part ment, Fac ulty of En gi neer ing, Egyp tian-Rus sian Uni ver sity, Cairo, Egypt 2 Phys ics De part ment, Fac ulty of Sci ence, Al-Azhar Uni ver sity, Cairo, Egypt 3 De part ment of Phys ics, Fac ulty of Sci ence, Aswan Uni ver sity, Aswan, Egypt 4 Nu clear Re search Cen ter, Egyp tian Atomic En ergy Au thor ity, Cairo, Egypt 5 Na tional In sti tute for Stan dards, Cairo, Egypt Sci en tific pa per http://doi.org/10.2298/NTRP1702120S The neu tron shield ing prop er ties of a bo rated high den sity glass sys tem was char ac ter ized ex - per i men tally. The to tal re moval mac ro scopic cross-sec tion of fast neu trons, slow neu trons as well as the lin ear at ten u a tion co ef fi cient of to tal gamma rays, pri mary in ad di tion to sec ond - ary, were mea sured ex per i men tally un der good geo met ric con di tion to char ac ter ize the at ten - u a tion prop er ties of (75-x) B2O3-1Li2O-5MgO-5ZnO-14Na2O-xBaO glassy sys tem. Slabs of dif fer ent thick nesses from the in ves ti gated glass sys tem were ex posed to a collimated beam of neu trons emit ted from 252Cf and 241Am-Be neu tron sources in or der to mea sure the at ten u - a tion prop er ties of fast and slow neu trons as well as to tal gamma rays. Re sults con firmed that bar ium bo rate glass was suit able for prac ti cal use in the field of ra di a tion shield ing. Key words: shield ing ma te rial, fast neu tron, slow neu tron, re moval cross-section, gamma ray IN TRO DUC TION portant is to mod erate the neu tron to low en er gies, where neu tron can readily be cap tured in ma teri als Ion iz ing ra di a tion has harm ful ef fects on hu man with high absorp ti on cross sec tion [8, 9]. The most ef - health and en viron ment., The same appli es to nu clear fec tive mod er a tors are el e ments with low atomic num- technol o gies acc om pa nied with sev eral haza rdous sit - ber; and there fore hy dro gen con tain ing ma te ri als are u ati ons for liv ing or ganism s. Therefore, it was neces - the major ef ficie nt com po nents of most neu tron sary to develop technol o gies for pro tecting against nu - shields, such as wa ter and par af fin. How ever, wa ter clear ra di a tion [1, 2]. Hence, the shield ing mate rial shields have the disad van tage of needing mainte - against nu clear ra di a tion was born and at tracted a nance; also, evap o rati on can lead to a poten ti ally dan - great deal of at tenti on [3, 4]. The most im portant radi a - ger ous loss of shield ing ef fec tive ness, while par af fin tions in the field of pro tec tive ma te ri als are neu trons is flam mable. If the neutron ener gy is suf ficie ntly and gamma-rays be cause they are the most pen e trating high, in elas tic scat ter ing with heavy nu clei can take for dif fer ent ma te ri als [5]. The ef fec tive ness of shield - place in which the recoil nu cleus is ele vate d to one of ing var ies with the type and ener gy of ra dia ti on and its excit ed states during the col li sion. The nucle us also accord ing to the de sired purpose of the shielding quickly de-ex cites; emitting a gamma ray, and the neu - [6]. Of ten a com bi na tion of three ma te ri als is de sir able tron loses a greater frac tion of its ener gy than it would that in cludes heavy ma te ri als, light ma te ri als, and neu - in an equiv a lent elas tic col li sion [10-12]. In elas tic tron-ab sorbing mate ri als to omit the slow neu trons scatter ing and the subse quent gamma ray emission through ab sorpti on of the neutron shield [7]. The play an im portant role in the shielding of high-ener gy shield ing of neu trons in tro duces many com pli ca tions neu trons. Ma te ri als with good in elas tic scat ter ing becaus e of a wide range of the ener gy that must be con- prop er ties are the heavy ele m ents, such as iron and sidered and the second ary produc ti on of gamma rays. lead, which used to offset this de crease in cross sec tion To choose neutron shielding mate ri als , the most im - with increa sed neu tron en ergy [13]. These mate ri als can cause a large change in neu tron en ergy af ter col li- * Cor re spond ing au thor; e-mail: y_elbashar@ya hoo.com A. A. Saeed, et al.: Neutron Shielding Prop erties of a Borat ed High-Density .. Nuclea r Technol ogy & Ra dia tion Pro tection: Year 2017, Vol. 32, No. 2, pp. 120-126 121 sion for high-ener gy neu trons, while they have a lit tle ef fect on the neu trons at lower ener gy, below 0.1 MeV [14, 15]. The 10B is ef fec tive for ab sorb ing epi ther mal neutrons (en ergy range 0.1 eV to 10 eV), and was in- cluded as a neutron ab sorber in vari ous mate ri als , e. g. bo rated graphit e, boron carbide, Boral, and bo ron ox- ide [16, 17]. Present work was focuse d on the study of im - pregna ti on of boron oxide in the glassy sam ples in ad- diti on to a study on the in fluence of barium in the form Fig ure 2. Ex per i men tal lay out of BaO (r = 5.73 gcm–3) on the at ten u a tion prop er ties of slow and fast neutrons as well as the to tal gamma crim i na tion ca pa bil ity. The neu tron-gamma crys tal rays. or ganic scin til la tion spec trom e ter with stilbene scintillator of di mension 4 cm ´ 4 cm was used to mea- sure the recoil proton and elec tron pulse am pli tude dis- SAM PLES PREP A RA TION tri bu tions. Ex per i men tal lay out of the mea sur ing sys - tem was pre sented in fig. (2). Fast neutron and total Pure, com mer cially avail able, raw ma te ri als gamma ray fluxes transm it ted through dif ferent bar ri- were used to pre pare a glassy system of the com pos ite ers of glass sam ples un der in vesti gati on were used to (75-x).B2O3-1Li2O-5MgO-5ZnO-14Na2O-xBaO per form the at ten u a tion prop er ties of such glass, (where x = 0, 10, 20, 30, 40, and 50 mol %) by the where the shielding param eter s of fast neutrons and to- melt-quenching technique with dim ensions 4 cm ´ 4 tal gamma rays were ob tained. cm and dif ferent thicknesse s (0.6 cm-1.02 cm). The dry powders were mixed, ho mog enize d and then melted at a tem pera ture of 1000 °C for 4 hours in por- Slow neu tron mea sure ments ce lain cru ci bles. Once a ho mo ge neous free bub ble liq - uid was obtai ned, it was poured into a stain less steel A collimated beam of neutrons emit ted from mold and then anneal ed at a tem pera ture of 400 °C for 241Am-Be source of acti v ity 0.2 TBq and neutron yield 4 hours to elim inate inter nal stress. Then the glass of (1.1-1.4)×107 neutrons per sec ond was slowed sam ples were cooled down to room tem pera ture . down, by a Perspex block, to measure the slow neutron Trans par ent and ho mog e nous glass sam ples were ob - at ten u a tion in the in ves ti gated glassy sys tem. The tained. Fi nally glass slab sam ples as shown in fig. (1) transm it ted beam of neutrons was measured under a were pol ished un til smooth surface s were ob served.